Mitochondrial quality control: an integrated network of pathways.

Mitochondria are organelles of eukaryotic cells with various functions. Best known is their role in energy transduction leading to the formation of ATP. As byproducts of this process, reactive oxygen species (ROS) are formed that can damage different types of molecules leading to mitochondrial dysfunction. Different quality control (QC) mechanisms keep mitochondria functional. Although several components involved in mitochondrial QC have been characterized in some detail, others remain to be integrated into what is currently emerging as a hierarchical network of interacting pathways. The elucidation of this network holds the key to the understanding of complex biological processes such as aging and the development of age-related diseases.